What is the management plan for a patient with a posterior circulation infarct?

Management of Posterior Circulation Infarct

Acute Reperfusion Therapy

For patients with basilar artery occlusion (BAO) presenting with NIHSS ≥6 and PC-ASPECTS ≥6, mechanical thrombectomy is indicated within 12 hours of last known well and is reasonable up to 24 hours. 1

Thrombectomy Indications by Time Window

• 0-12 hours from last known well: Thrombectomy is Class I indication for BAO patients with NIHSS ≥6, PC-ASPECTS ≥6, age 18-89 years 1
• 12-24 hours from last known well: Thrombectomy is reasonable (Class IIa) for BAO with NIHSS ≥6 and PC-ASPECTS ≥6 1
• Beyond 24 hours: Consider thrombectomy on case-by-case basis (Class IIb) for BAO with NIHSS ≥6 and PC-ASPECTS ≥6 1
• Age <18 or >89 years: Consider thrombectomy case-by-case (Class IIb) 1

Intravenous Thrombolysis

• Thrombolysis appears to have similar benefits and lower hemorrhage risks in posterior circulation compared to anterior circulation strokes 2
• Standard contraindications apply, including ischemic stroke within 3 months (except acute ischemic stroke within 3 hours) 1

Management of Acute Neurological Complications

Cerebellar Edema - Critical Emergency

Rapid deterioration from cerebellar infarcts with swelling is more common than anterior circulation and may be associated with sudden apnea from brainstem compression and cardiac arrhythmias. 1

• Surgical intervention: Decompressive suboccipital craniectomy to remove necrotic tissue is indicated for space-occupying cerebellar strokes 1
• Close observation in dedicated stroke or neurocritical care units is essential given the 25% rate of clinical deterioration 1

Medical Management of Brain Edema

• Restrict free water to avoid hypo-osmolar fluids 1
• Avoid excess glucose administration 1
• Minimize hypoxemia and hypercarbia 1
• Treat hyperthermia 1
• Avoid antihypertensive agents that induce cerebral vasodilation 1
• Elevate head of bed 20-30° to assist venous drainage 1

ICP Management When Edema Produces Increased Pressure

• Mannitol: 0.25-0.5 g/kg IV over 20 minutes every 6 hours, maximum 2 g/kg 1
• Hypertonic saline: Associated with rapid ICP decrease in patients with clinical transtentorial herniation 1
• Hyperventilation: Target mild hypocapnia (PaCO₂ 30-35 mmHg), though benefit is short-lived 1

Supportive Care and Monitoring

Critical Assessment Parameters

• Posterior circulation strokes present with non-specific symptoms including loss of consciousness, headache, nausea, vomiting, dizziness, double vision, hearing loss, slurred speech, vertigo, imbalance, and unilateral extremity weakness 1
• Physical examination may reveal ataxia, nystagmus, visual field defects, convergence nystagmus, skew deviation, and vertical gaze paralysis 1
• Important caveat: NIHSS has significant limitations in posterior circulation stroke, focusing on limb/speech impairments rather than cranial nerve lesions; patients with pc-ELVO can have NIHSS of 0 with only headache, vertigo, and nausea 1

Multidisciplinary Care Requirements

• Care in dedicated stroke or neurocritical care units with multidisciplinary teams composed of neurologists, neurointensivists, neurosurgeons, and dedicated stroke nursing 1
• Deterioration occurs in 25% of patients: one-third from stroke progression, one-third from brain edema, 10% from hemorrhage, 11% from recurrent ischemia 1

Secondary Prevention

Antiplatelet Therapy

• Aspirin is a potential intervention for deep vein thrombosis prevention but less effective than anticoagulants (Class IIa) 1
• Short-term dual antiplatelet therapy is recommended 2

Management of Vertebrobasilar Stenosis

• Basilar artery stenosis: Medical therapy is superior to stenting, which has high peri-procedural risk 2
• Intracranial vertebral stenosis: Best treated with medical therapy alone based on limited RCT data 2
• Extracranial vertebral stenosis: Stenting is an option for symptomatic stenosis, particularly for recurrent symptoms, though larger RCTs are needed 2

Aggressive Risk Factor Management

• High-intensity statin therapy 2
• Treatment of hypertension, diabetes, and other cerebrovascular risk factors 2
• Lifestyle interventions 2

Common Pitfalls to Avoid

• Misdiagnosis: 8% of patients hospitalized with presumed anterior circulation stroke within 5 hours of onset actually have posterior circulation infarcts 3
• Delayed recognition: Posterior circulation stroke patients are hospitalized later than anterior circulation patients (mean 168 vs 109 minutes) 3
• NIHSS limitations: Do not rely solely on NIHSS score; maintain high clinical suspicion with subtle symptoms like truncal ataxia, headache, or vertigo 1
• Imaging timing: Emergency CT helps differential diagnosis only when demonstrating early focal hypodensity; PC infarcts may not show early parenchymal changes 3
• Corticosteroids: No evidence that corticosteroids, diuretics alone, or glycerol improve outcomes in ischemic brain swelling 1